The invention relates to a detachable blocking device, in particular on a clamping tool, for example on a clamp, comprising a blocking element, which blocks the displacement capability of a rod at least in a detachment direction in a blocking position, and a detachment member, which displaces the blocking element into a release position when moved from a default position into a detachment position, in which release position the rod can be displaced at least in the detachment direction.
Furthermore, the invention also relates to a clamp comprising a rod bearing a first clamping jaw and a housing bearing a second clamping jaw, said housing having a drive member which, when actuated several times one after the other, displaces the rod progressively in a clamping direction which is opposed to the detachment direction.
Such a clamp is described in EP 0 997 232 B1. A blocking element, which in a blocking position blocks the displacement capability of the rod in the detachment direction, is located inside the housing. The two clamping jaws can be brought into a clamping position by the drive member. To this end the two clamping jaws can be moved towards one another or away from one another. In the latter case the clamp operates as a spreader clamp. A detachment member is provided which, when it is displaced from a default position, displaces the blocking member into a release position in which the rod can be displaced both in the detachment direction and also in the clamping direction opposed thereto. The blocking element is formed there by a steel plate having a window through which the rod is guided. In the blocking position the window edges dig into surface portions of the rod. If the detachment member is actuated, the blocking element is brought out of the tilted position, so that the rod can be displaced through the window. The detachment member cooperates there with the blocking element in such a way that by means of a displacement, occurring several times one after the other, of the detachment member beyond the detachment position the rod can be displaced progressively in the detachment direction. In this case the blocking element is pushed by the detachment member in the clamping direction over the track, wherein a return displacement spring is tensioned. The return displacement spring is capable of bringing the blocking element into a tilted position, in order to displace the blocking element together with the rod fastened thereto.